Rare Earth Metals

Atomic Radius

In the lanthanide series, each element that comes after the one next to it starting from the left has one more electron in the outer shell. This rule applies to the actinide series too.


The rare earths are silver, silvery-white, or gray metals. The metals have high electrical conductivity, which means they respond to electricity.

The rare earths share many common properties, and it’s difficult to separate them from each other if they combine.


Rare earth metals are generally used for electronics and making electronic devices. 

Boiling and melting points

Rare Metals has an inconsistent rate of increasing and decreasing boiling and melting points. The boiling point has a pattern of increasing and decreasing through out the graph, and the melting points seems to decrease and increase through out the graph.

Location on the periodic table

The elements were located in different places (out of the table) because if they were inside the periodic table, wouldn’t have enough space, and the elements would interrupt other groups and periods.


The rare earth metals can be found on the earth’s crust, combined with some minerals, such as igneous rocks.



Atomic Radius

Each halogen has 7 electrons in their outer shells, going down the group.

Melting and boiling points

As you go down the group, the halogens’ melting and boiling points increase. 


The reactivity of halogens decreases down the group, the more protons the less reactive it is, and so that means that astatine and Iodine would boil or melt faster than chlorine and fluorine; bromine is between the 4 of them. Halogens are highly reactive with alkali metals, and alkaline earths.


Chlorine plays a big part in the human body and covering 0.15% of the human body.

Fluorine, as a liquid is used as rocket fuel.

Bromine and Iodineare used to kill germs in water, and water companies use them mostly to make sure their water is fresh, clean and safe to drink.

Astatine is used to kill cancer cells.

Location on the periodic table

Periodic table elements each have been put in their groups, and not that they all share common forms, but they all have 7 electrons in their outer shell and have been divided in that form.

Abundance on earth

Halogens are found in the environment only in the form of compounds and need to be separated to have their original form.


Change of atomic radius:

As you go down the nonmetals elements the atomic radios increases by one electron shell. The element’s atomic radius from left to right increases, it gains one electron on the outermost shell.

Location On Period Table:

Nonmetals are in the last columns of the period table because the element’s outer shell has 4 to 8 electrons, the reason being  for having those elements on groups 13 to 18 on the periodic table.


Nonmetals are reactive, the nonmetals elements that are further way from the 8th group of the period table are the most reactive elements. The reason being is that elements that have less electrons on the outermost shell are most likely to have bonds, in some causes the elements have to lose or gain electrons to bond.


Nonmetals can be used for different purposes, for example oxygen is used for breathing, phosphorus is used to produce crackers, chloride is used to clean and purify water, nitrogen and potassium are used in fertilisers, graphite is used to conduct electricity and to produce lead, and etc…

Boiling and Melting point:

Most non-metals have low melting and boiling points, for example phosphorus, sulphur, and iodine have melting points of  44, 115 and 114 degrees Celsius and the boiling points of  280, 445, and 184 degrees Celsius . Even though carbon, silicon and boron have a very high melting and boiling points. Nonmetals have a very low density, because most of the elements are gases and liquids. Therefore the nonmetal elements will melt and boil faster.


Nonmetals are found naturally in the atmosphere, therefore they are not manmade elements. Some of the sulphur is accumulated about 1,000 feet beneath the Earth surface.  Nonmetals can be mixed into different elements, for example in some cases sulfur is mixed with rocks.

Alkali Metals

Change of atomic radius

In alkali metals, the atomic radius increases down the group. Each element has 1 electron in each outer shell because they are all in group 1.


The alkali metals are very reactive, but they are not found in elemental forms in nature. The elements are usually  found  in mineral oil, or paraffin oil. Alkali metals are mostly soft silver-colored, of low density.

Uses of Alkali Metals

Lithium is used to produce ceramics and glasses.

Devices that require batteries, for example  mobiles or computers contain Lithium batteries.

Sodium is used to produce salt , in the form of sodium chloride.

Sodium hydroxide is used to clean ovens.

Cesium is use to produce  military aircrafts.

A compound of rubidium, silver and iodine, is used to make film batteries.

Francium doesn’t have many uses, but it’s used in laboratories for experiments, and needs to be handled carefully, because it’s toxic.

Location on the periodic table

Elements in the same group have similar, but not identical characteristics. This is because they all have the same number of electrons in their outer shell. You can tell a lot about an element, if you know which group it belongs to.

Abundance on earth

All of the alkali metals are found in nature, but not in their pure forms. Most combine with oxygen and silica to form minerals in Earth, and have to get separated from the substance that they’re combined with. Alkali metals are soft silver-colored, with low density and can explode when combined with water.

Change of boiling point and melting point

All alkali metals are very soft and they have low melting and boiling points. Alkali metals melting and boiling points decrease down the group, so which means that Lithium has a lower boiling and melting point than Francium. As you go down, the alkali metals, the melting and boiling points get lower.

Note: Hydrogen is not an Alkali metal, but hydrogen is in group 1 because it only has 1 electron shell on the outer electron shell. 

Hydrogen (H)

Hydrogen doesn’t belong to a group on its own, because it has its own differences and needs to share the same form to fit in a group. Sometimes hydrogen is considered to be in the first group, or group 1.

Atomic Radius

Hydrogen has 1 shell, 1 proton and no neutrons, and since it doesn’t belong to a group, the atomic radius doesn’t change in its group; although it’s considered to be in the first group, with the alkali metals, because it has one shell.


Hydrogen is highly reactive in high temperatures with one electron and it tries to respond with other elements, to make compounds, like water. Hydrogen is a flammable substance and a colorless gas.

Uses of Hydrogen

Hydrogen can be used as a fuel for rockets.

Hydrogen and oxygen combine to make water, which is one of the most important compounds to the existent of the human race.

Location on the periodic table

Hydrogen is the first element on the periodic table, because it has 1 atom; that’s how elements have been arranged in the periodic table.

Is Hydrogen natural or man-made?

Hydrogen is natural, and can be found as a compound, and it needs to be separated to get pure hydrogen, by it self.

Change of boiling point and melting point

Melting point: -259.2°C

Boiling point: -252.762°C

Noble Gases

Change of Atomic Radius:

The atomic radius noble gases increases in a constant rate, as you go down the group the number of electron shells increases by 1 electron.

Location On Period Table:

Noble gases are located in the last group, because the outermost shell of the Noble gases’ elements is full. Basically noble gases is the 8th group in the period table because they have the outermost shell full;  theirs 8 electrons in the outer shell.


The noble gases are very unreactive elements , because the outer shell is fully configured. For example if scientists wanted to use any of the noble gases to create any kind of bonding, they wouldn’t be able to because the outermost shell is fully configured with the 8 electrons.  Even though the outer shell is full, it’s extremely stable and not expected to form chemical bonds and they have a very low chance of gaining or losing electrons.


Noble gases are mostly used for industrial functions. For example  helium is used to weaken the oxygen divers use to breathe, argon is widely used to supply an inert atmosphere for high-temperature metallurgical processes,  neon and argon are used to fill discharged tubes. Noble gases are also used in everyday life, helium is used to fill up balloons , neon to light up signs and argon is are used in lights bulbs.

Melting and Boiling point:

As you go down group the melting and boiling  point increases and the melting and boiling point of noble gases are very low compared to other elements.  The density of noble gases is low ,  gases melt and boil extremely fast because of their element’s physical property.

Chemical symbol Melting point °C Boiling point °C
Helium -272.2 -268.9
Neon -248.7 -246.1
Argon -189.4 -185.9
Krypton -156.6 -152.3
Xenon -111.9 -107
Radon -71 -61.8

Abundance on Earth:

Noble gases are not found easily, Noble gases are found naturally in small quantities in the atmosphere.

Transition Metals

Change of atomic radius:

The atomic radios of the elements increases by one electron shell in every element bellow and every element has the same number of electrons in the outer electron shell.

Location on the period table:

Transition Metals in the mid area of the period table because the placement depends on the number of electrons on the outer shell.


Transition metals do not react as much as Alkali Metals, because the elements have a protective oxide layer that demands them to remove at least 2 or 3 electrons, but Alkali Metals only need to remove 1.


Most transition metals are used for building materials, tools, vehicles, fighter aircraft, artificial hip joints, pipes in nuclear power stations and metal objects. The uncommon transition metals such as Copernicium, Darmstadtium  and Hassium  are only used for scientific research.Like all metals the transition elements are both ductile and malleable, and conduct electricity and heat. Iron, cobalt and nickel are the only elements that  are known to produce a magnetic field.

Melting and Boiling point:

The melting and boiling points increase as you go down the list except for the last 2 groups, for the last 2 groups the melting and boiling points decrease as you go down the list. But in the last few elements it starts increasing again. The density of transition metals is high, because metals are hard  elements .Which takes a higher temperature and longer to melt and boil.

Transition metals boiling points

Abundance on Earth:

Iron, copper and silver are the most abundant elements on Earth,they are found in nature and the uncommon transition metals are not found in nature. The  most important and useful transition elements are rare,for example  tungsten, platinum, gold, and silver. A few transition metals are manmade, for example technitium (Tc).

Alkaline Earth Metals


Change Of Atomic Radius:

The atomic radius of elements increases by one  electron shell in every element bellow . For example beryllium has 2 electron shells, magnesium has 3 electron shells and calcium has 4 electron shells.

Location on the periodic table:

Alkaline earth metals are located in the second group because all of the element in that group have 2 electrons on the outer shell.


Alkaline earth metals are high in reactivity series of metals, but alkali metals are more reactive.

Uses of Alkaline Earth Metals:

Beryllium is a very difficult to be extracted from ores , therefore is only used in certain items such as windows for x-ray tubes.

Magnesium is the only element in group 2 that is used on a large scale. It’s used in tracers, flares, and flammable bombs. Magnesium  is used to make car engines, pencil sharpeners, and many electronic devices such as laptops, and cell phones. It’s mixed with aluminium to produce a strong material used in aircrafts.

Calcium is used in constructions and found in  milk, cheese and dairy products.

Strontium  is used in fireworks (it produces scarlet flame colour) and it’s combined with chloride to make sensitive teeth toothpaste.

Barium is mixed with sulphate  to be used for radiocontrast agent for X-ray imaging of the digestive system.

Radium is used to produce radon gases (used for cancer treatments), neutron sources, luminous paints, and medical radioisotopes.

Melting and Boiling points:

The boiling and melting point does not have a consistent rate, it decreases and increases in every other element.

Element Boiling point Melting point
Be 2742K 1560K
Mg 1363K 923K
Ca 1757K 1115K
Sr 1655K 1655K
Ba 1000K 1000K
Ra 973K 973K

Location on the periodic table:

Alkaline earth metals are located in the second group because all of the element in that group have 2 electrons on the outer shell.

Abundance on Earth:

Beryllium is not very common because  it’s very difficult to extract from ores, the man made beryllium is not always available. Magnesium is the 11th most common element in the human body, magnesium ions are found  50% in bones. Calcium is a very common element, it’s found in milk and dairy products. Strontium is the 15th most common abundant element on Earth,  it’s usually found in the mineral celestite. Barium is not a very common element because it cannot be found easily in nature  because of its reaction to air, pure Barium can be found and removed from the mineral barite. Radium is common element, because of it’s uses but radium can be very harmful; it’s a decay product of uranium.